The iPhone has been in China for some time now. That is, if you count Hong Kong and Macau, or unlocked iPhones. But most people realize that a key for Apple is to gain penetration in the mainland Chinese market with the help of a major carrier. And it may be very close to such a deal, if pictures put up by carrier China Unicom are any indication.

It’s hard to know exactly what the presence of iPhone pictures on China Unicom’s site means, as every translation of the Chinese seems to be different. But given the recent reports floating around of Apple negotiating with China Unicom, it would certainly seem possible that the carrier will soon carry the iPhone. What’s more, a Chinese mobile industry source of ours says they hear that May 17, the China Telecom day, may be the day it’s formally announced.

While it might seem unlikely that details about an iPhone launch would leak out, given Apple’s track record of secrecy, “Chinese companies are not the best in keeping a tight lid,” says our source.

China Unicom is China’s second largest carrier, with over 125 million subscribers. It was thought that Apple badly wanted to partner with China’s largest carrier, China Mobile (which has almost a half billion subscribers), but that negotiations stalled.